Tubing blowout preventer



Sept. 3, 1968 M. l.. cRow ET AL 3,399,901

TUB ING BLOWOUT PREVENTER Filed May 13, 1965 2 Sheets-Sheet l Mor an LGrow Fre erick LeeAdams ATTORNEY Sept. 3, 1968 M L, CROW ET AL 3,399,901

TUBING BLOWOUT PREVENTER Filed May l5, 1965 2 Sheets-Sheet 2 f- L? 25 e""ff" "27 mlm 25/ /VH K25@ @5,111

El l-"T Q 1 JZZ lli-7 la@ v INVENTORS Morgan L.. Crow -}-Azzzr Fig-omFrederick Lee Adams ELF/MT BY 7W i,

ATTORNEY United States Patent O 3,399,901 TUBING BLOWGUT PREVENTERMorgan L. Crow and Frederick Lee Adams, Dallas, Tex., assignors toDresser Industries, Inc., Dallas, Tex., a corporation of Delaware FiledMay 13, 1965, Ser. No. 455,451 8 Claims. (Cl. 277-129) ABSTRACT OF THEDISCLOSURE This blowout preventer used in oil and gas wells has a hollowbody with a vertical bore and has coinciding lateral bores communicatingwith the vertical bore. In each lateral bore, there is a ram assemblyand a seal assembly.

In one form of the invention, the ram assembly, for moving the sealassembly relative to the vertical bore, has an end plate slideablewithin the lateral bore and has a feed screw housing also slideablewithin the lateral bore with an outer elongated threaded end eX- tendingfreely through the end plate. The feed screw housing is positionedwithin the lateral bore intermediate the end plate and a back plate. Afeed screw is attached rotatably to the back plate and extends throughthe feed screw housing and its outer elongated end. A yoke element isdropped through an opening in the housing delining the lateral bore tolock the end plate in place so that by tightening a nut on the outerelongated threaded end of the feed screw housing, the feed screw housingand the end plate are drawn together to compress a packing therebetweeninto sealing engagement with the lateral bore.

Each seal assembly includes a top plate and a lower plate positioned onopposite sides of a resilient sealing element. A pin extends through theback plate of the ram assembly and attaches the top plate thereto. Asimilar pin attaches the lower plate to the back plate, so that both thetop plate `and the lower plate are movable relative to the sealingelement.

This invention is concerned with a blowout preventer to be installed ona well headl to confine pressure in the well, and is particularlyconcerned with a blowout preventer intended to be installed on thetubing head at the top of the well, and is arranged to provide a sealabout a tubing string, a polished rod, wire line, or a like memberextending therethrough; or it may be provided with solid rams thereinwhich will close oil the passage above the rtubing head.

The blowout preventer hereinafter described and claimed is particularlydesigned for use in high temperature treatment of wells such as steaminjection, do-wn hole heater procedure, and in high temperatureproduction installations wherein both the pressure and temperature to beconfined are unusually high.

Means are provided to permit well pressure to communicate with the rearsides of the ram sealing members with the rams closed in order to allowthe well pressure to assist in making the seal, -to increase the sealingeffect proportional to the increase in pressure from below, or tocompensate for wear and deterioration of the seals on the rams.

It is, therefore, a primary object of the invention to provide a blowoutpreventer wherein the pressure in the well therebelow is allowed tocommunicate with the area behind the rams while the rams are in sealingposition to thereby .permit the well pressure to assist in maintaining atight `seal by the ram sealing elements.

Still another object of the invention is to provide in a tubing blowoutpreventei means whereby the rams are ice not sealed about their outsidediameter until they are in closed position thereby facilitating themovement of the rams into closed position.

Still another object of the invention is to provide in a tubing blowoutpreventer a ram assembly wherein the upper and lower support platesthereof are permitted to move longitudinally with reference to thesealing material while the ram is being moved to closed position tothereby permit constantly applied compressive sealing force on the ramsealing material while being moved to closed position.

Another object of the invention is to provide in a tubing blowoutpreventer ram sealing assemblies which are easily removed anddisassembled to permit the ram sealing element to be quickly and easilyreplaced.

A still further object of the invention is to provide in a tubingblowout preventer means for quickly and easily removing the ramassemblies and feed screws therefor to permit the changing of ramsealing assemblies and elements.

A general object of the invention is to provide a relativelyinexpensive, easily operable and easily serviceable, yet highlyeffective, blowout preventer, which will contine extremely highpressures encountered in steam injection, downhole heater and hightemperature production installations, as well as pressure in wellswherein high bottom hole pressure is encountered.

Other and further objects of the invention will become apparent uponreading the detailed specification hereinafter following and byreferring to the drawings annexed hereto.

A suitable embodiment of the invention is shown in the attached drawingswherein,

FIGURE I is a half-sectional elevational view of the blowout preventerassembly as it would appear when attached to the well head, and whereinthe rams are in sealing position about a polished rod,

FIGURE II is a perspective exploded view of one form of Ithe ram sealingassembly which includes the ram sealing element and the upper and lowersupport plates therefor,

FIGURE III is an end elevational view of the upper support plate for theram sealing assembly,

FIGURE IV is a cross-sectional elevational view taken along the lineIV-IV -of FIGURE III,

FIGURE V is a front end elevational view of the raw sealing element;

FIGURE VI is a side elevational view of the ram sealing element;

FIGURE VII is an end elevational view of the bottom support plate forthe ram sealing assembly;

FIGURE VIII is a cross-sectional elevational view taken along the lineVIII-VIII of FIGURE VII, and

FIGURE IX is an inner end elevational view of the back support plate forthe ram sealing assembly.

Numeral references are employed to indicate the various parts shown inthe drawings and like numerals indicate like parts throughout thevarious figures of the drawings.

Referring to the drawings, the numeral 1 indicates a hollow body havinga vertical bore 1a therethrough.

Coinciding laterally extending, hollow, cylindrically shaped portions 2and 3 are a part of, and extend from the body 1, providing alignedcircular passages right angularl-y intersecting the bore 1a. The body 1also includes hollow cylindrical neck portions 4 and 5 to which areconnected the upper flange 6 and the lower flange 13.

A sealing flange 7 is secured to the upper flange 6 by means of threadedstuds 11 which extend through coinciding passages in the ilanges 6 and 7and are secured thereto by -means of nuts 9 and 10.

A sealing ring 8 is compressed in coinciding grooves 8a and 8b in theopposed faces of 4the flanges 6 and 7, to provide a seal therebetween.

A section of pipe 12, which may communicate with surface equipment (notshown), is threadedly engaged at 12a to the sealing flange 7.

A flange 14, which may be a sealing flange, or which may be a flange atthe upper end of a tubing head, is secured to `the lower iiange 13 bymeans of threaded studs 15 which are secured thereto by means of nuts16.

A sealing ring 13a is pressed between coinciding grooves 13b and 13C,provided in the opposed faces of the anges 13 and 14, to provide a sealtherebetween.

The rarn sealing assembly (there being one disposed in each of thecylindrical housing portions 2 and 3), includes a deformable resilientsealing element 17 which has an elongated portion 17a with flat upperand lower sides terminated at the inner end, with substantially rightangular anges 18 and 19 (see FIGURES Il, V, and VI).

Bolt receiving passages 20 and 21 are provided through the flanges 18and 19 for the purposes hereinafter mentioned.

A semi-circular recess 23 is provided on the inner end of the extensionportion 17a, which is arranged to receive the polished rod 24, or othertubular or rod-like element, about which the ram sealing elements may besealed.

A top support plate 25 made of rigid material has a Hat lower face 25aand a rounded upper face 25b, and a semi-circular recess 26 on the innerend thereof. The forward part of the upper surface is sloped slightlyforward as indicated at 25c to facilitate the inward movement thereof.The top support plate is complementary to the ram sealing element 17 sothat when placed in the area between the flange 18 and the outer end ofthe extension portion 17a it will provide a continuous cylindricalsurface to t within the circular bore of the body portions 2 and 3; andthe recess 26 coincides with the recess 23.

Likewise, a bottom support plate 29 has a dat upper face 29a, a roundedlower face 29b and a semi-circular recess 30 on the outer end thereof.The bottom support plate 29 is complementary to the lower surface of theram sealing element 17 between the lower ange 19 and outer end of theportion 17a so that when assembled therewith it provides a continuouscylindrical surface for slidably fitting in the circular bores of theoutwardly extending portions 2 or 3 of the housing.

The circular ram back support plate 33 is made of rigid material and isarranged to abut against the rear side of the ram sealing element 17 andto slidably lit in the bores of the laterally extending portions 2 or 3of the housing.

The lower support plate 29 has a bore 32 therethrough which communicateswith an outer counterbore 31.

The pin 42 extends through the bore 32, counterbore 31, and passage 21of the sealing element 17. The pin 42 has a threaded end 43 thereonwhich is threadedly engaged with an interiorly threaded passage 37 inthe back support plate 33. The pin 42 has an enlarged head 44 thereonwhich engages the outer end of the bore 32 to limit longitudinalmovement therebetween.

The back support plate 33 has a passage 34 therethrough which isarranged to coincide with the passage 20 through the flange 18 of therubber sealing element 17, and with a bore 27 in the inner end of theupper support plate 25.

The bolt 39 extends through the aligned passages 34, 20 and 27, and hasa threaded end 40 thereon which may be threadedly engaged with thethreaded bore 28 in the inner end of the bore 27. The bolt 39 has anenlarged head 41 thereon, which is arranged to enter the counterbore atthe outer end of the bore 34, and limits the longitudinal movementbetween the bolt 39 and the back support plate 33.

A slot 36, which is open at its lower end, is provided on the rear faceof the back support plate 33 and has an overhanging wall 38 about theouter side thereof, which provides a space 38a in which the head 46 ofthe feed screw 45 may be inserted from the open end of the slot 36 toprovide a disengageable connection between the back plate 33 and thefeed screw 45.

The feed screw housing 47 is threadedly engaged at 45a about the feedscrew 45 and has an annular lip 45b on the inner end thereof which isslidably disposed with relation to the inner surface of the lateralhousing portions 2 -or 3, as the case may be.

A gland 49 is slidably disposed in the outer end of the housing portions2 or 3 and about the feed screw housing 47.

The resilient packing rings 50 are clamped between the annular flange45b on the feed screw housing 47 and the inner end of the gland 49.

To compress the packing 50, a packing nut 51 is threadedly engaged aboutthe threaded end 52 of the feed screw housing 47 to move the lip 45btoward the inner end of the gland 49.

Packing rings 55 are disposed about the reduced diameter extension 48 ofthe feed screw 45, said packing rings 55 and end spacer rings 55a beingdisposed within a counterbore 47a provided in the outer end of the feedscrew housing 47, and are abutted against a shoulder 4719 provided bysuch counterbore.

The packing 55 is retained in place by a gland 56 which may be movedinwardly against the spacer ring 55a to compress the packing 55 by meansof a gland nut 57 threadedly engaged about the outer end of the feedscrew housing 47.

A handle 58 is attached to the outer end of the feed screw 45 by meansof a pin 60 which passes through the inner end of the handle and spacerring 59 disposed about the extension 48 and the pin 60 is securedthereto by means of the snap rings about the ends thereof.

It will be noted that there is a bore 62 extending entirely through thebolt 42 which provides communication between the counterbore 31 and thespace 63 at the rear of the ram assembly. Sufiicient clearance isprovided between the lower inner side of the support plate 29 and thepolished rod 24 or other member about which the ram is disposed to allowcommunication between the area below the plate and counterbore 31.

The entire ram assembly, including the feed screw assembly, may beinserted in the lateral housing portions 2 or 3 and disengageablyattached therein by a U-shaped yoke 53, having spaced legs 53a thereon,which are arranged to pass through coinciding spaced passages 53b and53e in the wall of the housing portions 2 or 3 and through coincidingpassages (not shown) through the end plate 49. The yoke 53 may beretained in place by a retainer pin 54 passed through the ends thereof.

The operation and function of the device hereinbefore described is asfollows:

The ram is assembled in the manner shown in FIGURE I and inserted in theoutward extending housing portions 2 or 3, and is retained therein bythe yoke 53.

In order to move the sealing element 17 into sealing engagement aboutthe polished rod 24, or other rod-like or tubular element about which aseal is desired, the feed screw 45 is rotated by the handle 58, therebymoving it inwardly, Such rotation moves the back support plate 33inwardly, which in turn moves the sealing element 17, top support plate25 and `bottom support plate 29 toward the polished rod 24.

After engagement of the inner surfaces of ram sealing elements 17 withthe polished rod 24, the continued forward movement of the back supportplate 33 will compress and move the ram sealing element around thepolished rod to provide a seal thereabout. The compression of thesealing element 17 also causes expansion outwardly to provide a sealwith the interior diameters of the housing portions 2 and 3.

As the seal 17 is expanded the pin 39 is permitted to move rearwardlythrough the bores 20 and 34; and the pin 42 is permitted to moveforwardly through the bores 32 and 21 and counterbore 31. Therefore, theupper support plate 25 and lower support plate 29 are allowed to movewith reference to the sealing element 17 as the sealing element is movedinwardly and expanded about the polished rod 24. Therefore, adequatesealing expansion is permitted about the member around which the sealingelements are sealed.

While the deformable sealing elements 17 are sealed about the member 24,it will be observed that pressure from below the sealing element ispermitted to pass through the passage 62 through bolt 42 to communicatewith the area 63 behind the ram sealing assembly. Therefore, thepressure from below the ram sealing assembly assists in moving the raminwardly, and in maintaining it in sealing position. Any increasedpressure below the ram sealing assembly will act against the inner endthereof to further increase the seal between same and the polished rod24, or other element about which the seal is made.

The ram assembly may be replaced, or may be removed for replacement ofthe resilient sealing element 17 by simply loosening nut 51, removingthe yoke 53 and withdrawing same from the housing portion 2 or 3.

A ram sealing assembly, consisting of the resilient sealing element 17,top plate 25, bottom plate 29, back plate 33, and bolts 42 and 39 may beremoved from a ram assembly and replaced in its entirety by another sealassembly. Individual rubber sealing elements 17 may be quickly andeasily replaced in the sealing assembly by simply removing the bolts 39and 42. to disassemble the sealing element 17 from the plates 25, 29,and 33.

Other and further embodiments of our invention may be devised withoutdeparting from the spirit and scope of the appended claims.

Having described our invention we claim:

1. In a blowout preventer, a hollow body having a vertical boretherethrough; coinciding lateral bores cornmunicating with the verticalbore; a ram assembly disengageably supported in each lateral bore; aseal assembly disengageably attached to the end of each ram assembly;means to move the seal assembly inwardly toward the vertical bore; meansdefining a passage communicating between the area below the sealassembly and the area behind the seal assembly to allow pressure frombelow the seal assembly to assist in moving the seal assembly inwardly,said ram assembly to move the seal assembly includes an end plateslideable within said lateral bore, feed screw housing means slideablewithin said lateral bore and having an outer elongated threaded endextending freely through the end plate, a feed screw threadedly engagedin the feed screw housing means; means disengageably attaching the feedscrew to the back plate; packing means between said feed screw housingmeans and said end plate; means threaded on said outer elongatedthreaded end to move said feed screw housing means and said end platerelative to each other to compress said packing means into sealingengagement with said lateral bore; quick detachable means slideablethrough the end plate to lock the end plate relative to said lateralbore, and means to rotate the feed screw from exteriorly of the lateralbore.

2. In a blowout preventer, a hollow body having a vertical boretherethrough; coinciding lateral bores communicating with the verticalbore; a ram assembly disengageably supported in each lateral bore; aseal assembly disengageably attached to the inner end of each ramassembly, each seal assembly including a top plate, a lower plate, aback plate and a resilient sealing element disposed between the saidplates, an upper connecting pin slideably extending through the backplate and the resilient sealing element and engaged with the top plate;and a lower connecting pin slideably extending through the lower plate,and a resilient sealing element and engaged with the back plate, so thatthe top plate and the lower plate are moveable relative to the sealingelement, the edges of the sealing element being exposed between theedges of the said plates; means to move the seal assembly inwardlytoward the vertical bore; and means defining a passage communicatingbetween the area below the seal assembly and the area behind the sealassembly to allow pressure from below the seal assembly to assist inmoving the seal assembly inwardly.

3. The combination called for in claim 2 wherein a passage extendsthrough the lower connecting pin.

4. The combination called for in claim 1 wherein the means disengageablyattaching the feed screw to the back plate comprises an undercut slot inthe rear face of the back plate; and a head on the end of the feed screwinsertable in the slot from the outer open end thereof.

5. The combination called for in claim 1 wherein the ram assembly isdisengageably attached in the bore by a withdrawable yoke extendingthrough the wall of the lateral bore and a part of the ram assembly.

6. In a blowout preventer, a hollow body having a vertical boretherethrough, coinciding lateral bores communicating with the verticalbore, a ram seal assembly including, a resilient seal member having acylindrical end, an upper and lower relieved area on each side thereofspaced from the cylindrical end providing an elongated thinner portionhaving upper and lower flat sides, upper and lower flanges on thecylindrical end, and diamctrically opposite upper and lower boltreceiving passages through the flanges; an upper support plate disposedslideably in the upper relieved area, said upper support plate having aflat inner side coinciding with the upper Hat side of the thinnerportion, and a curved outer side coinciding with the cylindrical surfaceon the upper flange; a lower support plate disposed slideably in thelower relieved area and having a at upper side coinciding with the lowerflat side of the thinner portion, and a curved outer side coincidingwith the cylindrical surface on the lower flange; a circular backsupport plate disposed against the inner end of the seal member andhaving an outer surface coinciding with the outer cylindrical surface onthe cylindrical end; upper and lower aligned bolt receiving passages inthe upper, lower and back support plates, said upper aligned passagescoinciding with the passage through the upper flange, and the loweraligned passages coinciding with the passage through the lower flange, apin slideably extending through the upper ange passage and thecoinciding passage -in the back plate and being threadedly engaged inthe coinciding passage in the top plate; and a pin slideably extendingthrough the passage in the lower plate and the coinciding passage in thelower flange and being threadedly engaged in the lower passage in thebackI support plate.

7. The combination called for in claim 6 with the addition of anundercut slot on the rear face of the back plate which opens from theouter edge of the plate.

8. The combination called for in claim 6 with the addition of a passagethrough the lower pin.

References Cited UNITED STATES PATENTS 2,293,153 8/ 1942 Lorehn et al277-129 2,427,073 9/ 1947 Schweitzer 277-129 2,527,068 10/1950 Murray277-185 3,102,709 9/ 1963 Allen 277-129 X 3,272,222 9/1966 Allen 251-1 XSAMUEL ROTHBERG, Primary Examiner.

